Devices and methods for selective hair removal have long existed in the fields of cosmetology and medicine. Wax based preparations are widely used to remove body and facial hair. Cold wax techniques have limited effectiveness, and hot wax preparations are typically painful to apply and can be damaging to the skin. Chemical depilatories are cumbersome to use and can also be insulting and damaging to human skin tissue.
U.S. Pat. No. 4,983,175, granted to Daar et al., discloses an electrically powered depilatory device which employs elongate elements, i.e. threads or strings, in a mutually twisted engagement . A motor within the housing of the device drives the elongate elements in motion around and beyond the linear action of the twisted engagement to cause a continuous twisting action. This twisting action engages the strands of a subject's hair between the elongate elements. The hair is then intertwined within the mutually twisted engagement of the elongate elements. The position of the twisted engagement remains static in relationship to the housing of the depilatory device, which causes the hair to be wound around the twisted engagement and for the hair to be laterally displaced from its root by a double action hair removal.
The static positional relationship of the twisted engagement to the housing, in the invention of Daar et al., limits the depilatory device to removing hair from only a small portion of a subject's skin at a time. The hair removal process of the application of a device designed according to Daar et al. therefore delivers a low level of efficiency to a user. In addition, the inclusion of an electric motor in the device of Daar et al. limits its safe and effective use in either moist environments or in combination with lotions and emollients. Furthermore, the need for electric power requires a user to have either portable batteries or an available source of compatible electric power.